A liquid crystal display panel generally includes an array substrate, a color filter substrate, and liquid crystals provided between the array substrate and the color filter substrate. The array substrate and the color filter substrate both include an alignment layer configured to restrict arrangement of liquid crystal molecules, so that the liquid crystal molecules, when not in an electric field, are arranged in a preset initial direction.
At present, the alignment layer generally may be manufactured by rubbing or exposing a polyimide film (PI film), that is so called “rubbing alignment” or “photoinduced alignment”. A photoinduced alignment process is a process in which PI film is irradiated with UV light to cause photo polymerization, photo-isomerization or photo-decomposition reaction in polyimide molecules in the PI film, so as to bring on anisotropy to induce the alignment of the liquid crystal molecules. In the photoinduced alignment process, the PI film does not contact other media. Hence problems such as scraping contamination and electrostatic breakdown in a rubbing alignment process will not occur.
FIG. 1 illustrates a schematic diagram of an existing photoinduced alignment apparatus.
As shown in FIG. 1, the photoinduced alignment apparatus includes a supporting base 1, an exposure device 2, a diving mechanism (not shown in the figure) and a loading and unloading device 4. The supporting base 1 are used to support a substrate S, the exposure device 2 exposes a substrate S placed on the supporting base 1, the driving mechanism drives the supporting base 1 to move, and the loading and unloading device 4 is used to load a substrate S onto the supporting base 1 and to unload a substrate S from the supporting base 1.
When the alignment layer is manufactured by using the photoinduced alignment apparatus shown in FIG. 1, in a first stage, the loading and unloading device 4 loads a substrate S having a PI film prepared thereon to the supporting base 1, and detects whether the substrate S is placed accurately. In the first stage, a shielding device is used to shield a light exiting area of the exposure device 2, to avoid exposing only a portion of the substrate S and thus to avoid influencing the uniformity of the exposure process. In a second stage, the shielding device is removed from the light exiting area of the exposure device 2, and then, the driving mechanism drives the supporting base 1 to move from an initial position 1-0 to an end position 1-1. During this process, each area of the substrate S is exposed by the exposure device 2, so that photo polymerization, photo-isomerization or photo-decomposition reaction occur in the PI film on the substrate S, so as to bring on superficial anisotropy. In a third stage, the driving mechanism drives the supporting base 1 to move back to the initial position 1-0, and the loading and unloading device 4 unloads the substrate S from the supporting base 1.
During manufacturing an alignment layer by using the above photoinduced alignment apparatus, when the substrate S is loaded or unloaded, when it is detected whether the substrate S is placed accurately, and when the shielding device shields the light exiting area of the exposure device 2, the exposure device 2 cannot perform irradiation on the substrate S on the supporting base 1 to expose the substrate S. As a result, in each period of manufacturing the alignment layer, the proportion of exposure time is small, thus the utilization of the exposure device 2 is low.